Method of teaching eyepoints for wire bonding and related semiconductor processing operations

ABSTRACT

A method of teaching an eyepoint for a wire bonding operation is provided. The method includes (1) selecting a group of shapes from a region of a semiconductor device for use as an eyepoint, and (2) teaching the eyepoint to a wire bonding machine using at least one of (a) a sample semiconductor device, or (b) predetermined data related to the semiconductor device. The teaching step includes defining locations of each of the shapes with respect to one another.

CROSS REFERENCE

This application claims the benefit of U.S. patent application Ser. No.12/093,403, which is a U.S. National Phase application of PCTApplication No. PCT/US2007/063850, filed on Mar. 13, 2007, the contentof which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to wire bonding systems, and moreparticularly, to improved eyepoint teaching methods for use in wirebonding systems.

BACKGROUND OF THE INVENTION

U.S. Pat. Nos. 5,119,436 and 6,869,869 relate to wire bonding systemsand associated vision systems, and are hereby incorporated by referencein their entirety.

In the processing and packaging of semiconductor devices, teachingoperations using vision systems are often utilized. For example, beforea wire bonding operation is performed on a batch of semiconductordevices (e.g., devices such as a semiconductor die mounted on aleadframe), it is typically desired to “teach” an eyepoint (or multipleeyepoints) of a sample device. By “teaching” the sample device, certainphysical data related to the sample device is stored (e.g., in thememory of a wire bonding machine). This physical data is used as areference during processing of the batch of devices, for example, toensure proper positioning or alignment of each of the batch ofsemiconductor devices to be processed (e.g., to be wire bonded).

Thus, in the context of a wire bonding operation, a wire bonding machineuses a vision system (e.g., a Pattern Recognition System or PRS) to finda previously taught pattern (e.g., an eyepoint, a fiducial, etc.) foraligning a semiconductor device after it is presented at the bond siteand before the wires are bonded (e.g., before the wires are bondedbetween the semiconductor device and a leadframe supporting thesemiconductor device). Traditionally, an eyepoint is taught on the wirebonding machine based on a sample device where an operator targets anarea on the sample device with a teach window. Certain conventionaltechniques (e.g., algorithms) are used in conjunction with a visionsystem to scan the targeted eyepoint.

One conventional teaching technique relates to scanning the sampledevice (e.g., a selected portion of the sample device) using anormalized grayscale correlation system (i.e., NGCS). Through such atechnique, grayscale values are assigned based on what a vision systemdetects is present at each location. For example, when a bond pad of asemiconductor device is scanned grayscale values are assigned to thescanned location. After the desired region is scanned, a library ofgrayscale values (associated with corresponding scanned positions) isstored. When the actual semiconductor devices of this type are to bewire bonded, the vision system detects the grayscale values at each ofthe scanned locations and compares these grayscale values to thosestored in the library during the teaching process.

Another conventional teaching technique relates to scanning the sampledevice (e.g., a selected portion of the sample device) and detectingindividual edges defined within the scanned region (i.e., edge-basedpattern matching). Through such a technique, values are defined based onwhat a vision system detects is present at each location. For example,when a bond pad of a semiconductor device is scanned an edge value isassigned to the scanned location. After the desired region is scanned, alibrary of edge values (associated with corresponding scanned positions)is stored. When the actual semiconductor devices of this type are to bewire bonded, the vision system detects the edge values at each of thescanned locations and compares these values to those stored in thelibrary during the teaching process.

Using either of these conventional methods, a weighted score is given toeach device to be wire bonded, where the score is a function of acomparison of the taught sample device to the actual device to be wirebonded. If the score exceeds a certain threshold value, the device isacceptable and will be processed (e.g., wire bonded); however, if thescore is below the threshold value, automatic operation typically doesnot continue. For example, the operator may be notified of the lowscore. Further, a subsequent location or eyepoint may be attempted toobtain an acceptable score. Further still, an alternate algorithm orrecovery sequence may be attempted.

Unfortunately, there are a number of problems associated with each ofthese conventional techniques. A practical reality of semiconductordevices is that different devices from the same batch (or differentbatches) may exhibit different visual properties even though they areconsidered to be the same device and have the same electrical functionalproperties. For example, the surface color or texture may vary fromdevice to device. Such variations may arise due to slightly differentfabrication processes used by the different suppliers of the samedevice. Such variations often result in devices that appear quitedifferent from each other in terms of contrast and reflectivity (e.g.,non-linear variations in reflectivity). Thus, the weighted scores thatresult from conventional pattern matching techniques may be lowerbecause of such variations (e.g., due to the differences in reflectivityof the devices to be wirebonded when compared to the sample taughtdevice). Therefore, although scores are typically used to omit falsefinds, conventional pattern matching techniques (e.g., NGCS systems,edge-based pattern matching systems, etc.) tend to result in scoresbelow the threshold value even if the device is acceptable for furtherprocessing. Another problem resulting from such variations amongstsemiconductor devices (e.g., surface variations among the devices) maybe an undesirably low mean time between assists MTBA), leading to lowerproductivity of the automatic wire bonding equipment.

Thus, it would be desirable to provide improved methods of teachingeyepoints for semiconductor device processing, and improved methods ofprocessing semiconductor devices using the eyepoints.

SUMMARY OF THE INVENTION

According to an exemplary embodiment of the present invention, a methodof teaching an eyepoint for a wire bonding operation is provided. Themethod includes (1) selecting a group of shapes from a region of asemiconductor device for use as an eyepoint, and (2) teaching theeyepoint to a wire bonding machine using at least one of (a) a samplesemiconductor device, or (b) predetermined data related to thesemiconductor device. For example, such predetermined data may be apriori data (e.g., CAD data, historical data, etc.), or may bepredetermined in that it is determined just prior to the teaching step.The teaching step includes defining locations of each of the shapes withrespect to one another.

According to another exemplary embodiment of the present invention, amethod of operating a wire bonding machine is provided. The methodincludes (1) selecting a group of shapes from a region of asemiconductor device for use as an eyepoint, and (2) teaching theeyepoint to the wire bonding machine using at least one of (a) a samplesemiconductor device, or (b) predetermined data related to thesemiconductor device. The teaching step includes defining locations ofeach of the shapes with respect to one another. The method also includes(3) indexing a first semiconductor device configured to be wire bondedinto a predetermined position of the wire bonding machine, and (4)scanning selected portions of the first semiconductor device using avision system of the wire bonding machine, the selected portionscorresponding to the taught eyepoint.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is best understood from the following detailed descriptionwhen read in connection with the accompanying drawing. It is emphasizedthat, according to common practice, the various features of the drawingare not to scale. On the contrary, the dimensions of the variousfeatures are arbitrarily expanded or reduced for clarity. Included inthe drawing are the following figures:

FIG. 1 is a top view of a portion of a semiconductor device inaccordance with an exemplary embodiment of the present invention;

FIG. 2 is a top view of a portion of another semiconductor device inaccordance with an exemplary embodiment of the present invention;

FIG. 3 is a top view of a portion of another semiconductor deviceincluding an eyepoint in accordance with an exemplary embodiment of thepresent invention;

FIG. 4 is a top view of the portion of the semiconductor device of FIG.3 with certain areas masked in accordance with an exemplary embodimentof the present invention;

FIG. 5 is a top view of a portion of another semiconductor deviceincluding an eyepoint in accordance with an exemplary embodiment of thepresent invention;

FIG. 6 is a top view of a portion of the semiconductor device of FIG. 5selected as an eyepoint in accordance with an exemplary embodiment ofthe present invention;

FIG. 7 is a corrected version of the eyepoint of the semiconductordevice of FIG. 5 in accordance with an exemplary embodiment of thepresent invention;

FIG. 8 is a top view of the portion of the semiconductor device of FIG.7 with certain areas masked in accordance with an exemplary embodimentof the present invention;

FIG. 9 is a top view of a portion of another semiconductor deviceincluding an eyepoint in accordance with an exemplary embodiment of thepresent invention;

FIG. 10 is a top view of a portion of the semiconductor device of FIG. 9selected as an eyepoint in accordance with an exemplary embodiment ofthe present invention;

FIG. 11 is a corrected version of the eyepoint of the semiconductordevice of FIG. 9 in accordance with an exemplary embodiment of thepresent invention;

FIG. 12 is a top view of the portion of the semiconductor device of FIG.11 with certain areas masked in accordance with an exemplary embodimentof the present invention;

FIG. 13 is a top view of a portion of another semiconductor deviceincluding an eyepoint in accordance with an exemplary embodiment of thepresent invention;

FIG. 14 is a top view of a portion of the semiconductor device of FIG.13 selected as an eyepoint in accordance with an exemplary embodiment ofthe present invention;

FIG. 15 is a corrected version of the eyepoint of the semiconductordevice of FIG. 13 in accordance with an exemplary embodiment of thepresent invention;

FIG. 16 is a top view of the portion of the semiconductor device of FIG.15 with certain areas masked in accordance with an exemplary embodimentof the present invention;

FIG. 17 is a top view of a portion of another semiconductor deviceincluding an eyepoint in accordance with an exemplary embodiment of thepresent invention;

FIG. 18 is a top view of the eyepoint portion of the semiconductordevice of FIG. 17 with certain areas masked in accordance with anexemplary embodiment of the present invention;

FIG. 19 is a top view of a semiconductor device including two eyepointsin accordance with an exemplary embodiment of the present invention;

FIG. 20 is a top view of a portion of semiconductor device bonded to aleadframe in accordance with an exemplary embodiment of the presentinvention;

FIG. 21 is a flow diagram illustrating a method of teaching an eyepointfor a wire bonding operation in accordance with an exemplary embodimentof the present invention; and

FIG. 22 is a flow diagram illustrating a method of operating a wirebonding machine in accordance with an exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

According to an exemplary embodiment of the present invention, a methodfor generating a geometric feature-based pattern used for positioningand/or alignment of semiconductor devices in wire bonding equipment isprovided. The method defines a technique for generating an eyepointusing invariant features of the patterns on the semiconductor diesurface. Such an approach increases the robustness of finding thepattern on semiconductor devices that have certain variations (e.g.,variations in surface reflectivity). Further, the generated eyepoint maybe constructed using synthetically created features (e.g., using apriori data such as CAD data) or can be extracted from the actual partimage. Unlike traditional PRS systems (e.g., grayscale pattern matching,geometric pattern matching), the proposed method effectively capturesthe invariant features inside an image. A model (e.g., stored in thememory of the wire bonding machine) created using the invariant features(and the relationship of the invariant features with respect to oneanother) is more robust for handling device variations in an automatedwire bonding production environment in comparison to conventionaltechniques.

Eyepoints generated using the various exemplary methods disclosed hereinmay be used as a primary eyepoint or backup eyepoint in a PRS, forexample, using pad information (or other geometric or shape information)learned during the eyepoint teaching process. The generated eyepoint(and the region of the semiconductor die) may be selected (1)automatically by the PRS by choosing a region on the semiconductordevice that has good pad geometric information (e.g., a region includinga vertical row of pads and a horizontal row of pads), and/or (2) atleast partially through operator intervention in choosing this regionwith desirable pad information.

In an example where the PRS automatically generates the eyepoint, shapes(e.g., bond pad shapes of any type such as rectangular, octagonal,round, etc.) and relative locations of the shapes may be obtained fromthe device data (e.g., CAD data) through an off-line programming tool orthe like. Alternatively, such shapes (and relative locations of theshapes) may be extracted automatically, using a vision system, afterobserving the sample device. If a sufficiently complete digitaldescription of the semiconductor die (i.e., predetermined device data)is available, an algorithm may be used to select appropriateshapes/features for inclusion in the eyepoint, and then the algorithmmay be used to bind the selected shapes/features together (e.g., usingthe relative positions of the shapes/features). Using such a method a“visionless teach” process (i.e., an offline programming method) isprovided which utilizes little or no learning activity on the wirebonder itself. Of course, it may be desired to confirm an eyepointtaught using such an offline program with a sample device on the wirebonding machine. In such a visionless teach system, it may be possibleto reduce the requirements of the optical system of a wire bondingmachine. This is because wire bonding machines often employ complexvision systems, sometimes with varying levels of magnification, in orderto perform the teach operation; however, if the teach operation wereperformed in a visionless manner using pre-existing data, the complexity(and cost) of the vision system may be reduced. For example, in a wirebonding machine that conventionally uses two magnification levels (twooptical systems such as a “high magnification system” and a “lowmagnification system”), the high magnification system may be able to beomitted from the wire bonding machine. This may be the case because thehigh magnification system is often used to obtain detailed views oftaught area, such as the small (e.g., sub-pixel sized) gaps betweenadjacent bond pads. According to certain exemplary embodiments of thepresent invention, using a “visionless” teaching process such detail maynot be desired (e.g., because of the cost of the high magnificationsystem).

In an example where operator intervention is utilized in generating theeyepoint, the operator may be assisted by an accurate motion system anda calibrated PRS. For example, the motion system and PRS system mayperform a teaching process (e.g., a bond pad teaching process) based onparameters provided by the operator. Such a method may be utilized, forexample, (1) when no adequate description of the semiconductor device isavailable, and/or (2) when features without a well defined geometry areto be included in the eyepoint. Such a teaching process may involve, forexample, moving to each of the desired shapes/features in turn andacquiring the desired data from an image of the desired shape/feature.Once all of the shapes/features have been taught, an eyepoint may beestablished using the combination of the taught shapes/features andtheir respective locations/positions within an established frame ofreference.

Regardless of how the eyepoint is generated, after the teaching process,shape information such as bond pad size, bond pad location, shape,polarity and other properties are available inside the PRS system.Further, besides the individual shape information (e.g., individual bondpad shape information), the geometric relationship between those shapes(e.g., between those bond pads) may also be obtained from the motionsystem and/or calculated using the PRS system.

As suggested above, in the taught region (e.g., the eyepoint),synthetically created shapes/pads could replace information regardingreal shapes/pads (i.e., image based pad models). More specifically, suchsynthetically created shapes/pads are provided by using available datarelated to the semiconductor device (e.g., a priori data such as CADdata). Such synthetically created shapes/pads may give a betterrepresentation of an average shape/pad because it contains all thegeneralized characteristics of numerous shapes/pads (and perhaps withoutcertain defects of a sample device that may otherwise be used to teachan eyepoint). Further, proper masking techniques may be used toeliminate certain areas of the selected region of the semiconductordevice that tend to change from device to device. Further still, atechnique which gives more weight to a certain region of thesemiconductor device (e.g., a peripheral pad area of the die) as opposedto other areas of the device may be used to make the eyepoint morerobust.

The shapes included in the generated eyepoints according to the presentinvention include, for example, bond pad shapes, groups of bond padsthat form a pattern, traditional eyepoint shapes (e.g., a cross, acircle, a square, etc.), circuitry with a defined shape, and/orarbitrary surface features on the die that are distinct, amongst others.Further, two or more of these (or other) exemplary shapes may becombined for inclusion in the generated eyepoint.

The algorithm used to establish the eyepoint may include a number ofdifferent strategies, for example, (1) a minimum number ofshapes/features may be predetermined in an algorithm, and when thispredetermined number of shapes/features has been taught, the algorithmmay move to another portion of the process such as calculating thelocation of the taught shapes/features with respect to a frame ofreference and/or with respect to each other; (2) defining certainshapes/features as required during the teach process such that a failureto locate such features may result in a failure to define the eyepoint;(3) employing a weighting system such that certain shapes/features aregiven weights based on their respective criticalities orpredictabilities where such a weighting system is used to define a scoreof a semiconductor device to be processed; (4) if all of the desiredshapes/features selected for inclusion in the eyepoint fit within asingle field of view of the vision system (e.g., the imaging camera)then a single find operation may be used to locate the eyepoint; (5) ifthe desired features can not fit the field of view, individual features(e.g., individual bond pads of the eyepoint) may be located after whicha complete taught pattern (e.g., including the relative locations of theindividual features) can be obtained from combining the data of theindividually located features; and/or (6) applying multiple (and perhapsredundant) teach algorithms during the teach phase to improvereliability. Any combination of these strategies (amongst others) may beemployed within the scope of the present invention.

FIG. 1 is a top view of a portion of semiconductor device 100 (theillustrated portion is the lower left hand portion of a semiconductordie as viewed from above). Semiconductor device 100 includes a number ofbond pads arranged about the periphery of the device. For example, suchbond pads include bond pads 100 a, 100 b, 100 c, 100 d, 100 e, 100 f,100 g, 100 h, 100 i, 100 j, 100 k, 100 l, and 100 m. Semiconductordevice 100 also includes circuit region 102 and circuit region 104. Asis known to those skilled in the art, circuit regions on a semiconductordevice (e.g., a semiconductor die) may include wiring patterns,conductive traces, and the like.

In order to process semiconductor device 100 on a wire bonding machine(e.g., in order to bond wire loops between bond pads of device 100 and asecond bonding location, where the second bonding location may be leadson a leadframe on which device 100 is mounted), it is desirable to alignsemiconductor device 100 on the wire bonding machine using aneyepoint(s) previously taught to the wire bonding machine. Of course,the desire for such alignment applies to various other semiconductorprocessing techniques including, for example, stud bumping, die to diewire bonding, inspection of wire bumps/loops, etc.

As discussed above, a practical reality of semiconductor devices is thatdifferent devices may exhibit different properties even though they areconsidered to be the same device. For example, FIG. 2 is a top view of aportion of another semiconductor device 200. Semiconductor device 200,while provided by a different manufacturer than device 100 of FIG. 1, isconsidered to be the same device as semiconductor device 100 illustratedin FIG. 1 from the perspective of a wire bonding machine. Similar to thebond pads of semiconductor device 100, semiconductor device 200 includesa number of bond pads such as bond pads 200 a, 200 b, 200 c, 200 d, 200e, 200 f, 200 g, 200 h, 200 i, 200 j, 200 k, 200 l, and 200 m. Further,similar to circuit regions 102 and 104 of semiconductor device 100,semiconductor device 200 includes circuit regions 202 and 204. From theviewpoint of a vision system, circuit regions 102 and 104 ofsemiconductor device 100 appear as single components or regions having acommon physical appearance; however, because of variations in thesurface of the two devices (i.e., devices 100 and 200), the same visionsystem may see circuit regions 202 and 204 of semiconductor device 200as including numerous discrete portions. For example, as shown in FIG.2, circuit region 202 is viewed as including portions 202 a, 202 b, and202 c (amongst others). Likewise, circuit region 204 includes portions204 a, 204 b, and 204 c (amongst others).

Thus, while semiconductor device 100 and semiconductor device 200 areoperationally the same, because of one of a number of potential reasons(e.g., surface color, surface texture, etc.), the vision system seesthem as quite different. Now, assume that an eyepoint for a wire bondingoperation is taught using a portion semiconductor device 100 includingcircuit region 102 or 104. When it is time to process (e.g., wire bond)semiconductor device 200 using the eyepoint taught from semiconductordevice 100, a number of potential problems may result (e.g., the scorefor semiconductor device 200 being below a threshold value even thoughthe device is acceptable for further processing, an undesirably low MTBAfor devices such as semiconductor device 200, etc.).

According to certain exemplary embodiments of the present invention, aneyepoint is selected with the intention that the eyepoint does not varyfrom device to device, regardless of differences in surfacecolor/texture and the like. For example, a group of shapes from a regionof a semiconductor device may be selected for use as an eyepoint. Whenteaching the eyepoint to a wire bonding machine using a samplesemiconductor device, locations of each of the shapes with respect toone another is defined.

For example, FIG. 3 illustrates such an eyepoint selection in accordancewith an exemplary embodiment of the present invention. FIG. 3illustrates semiconductor device 300 including a number of bond padssuch as bond pads 300 a, 300 b, 300 c, 300 d, 300 e, 300 f, 300 g, 300h, 300 i, 300 j, 300 k, 300 l, and 300 m. Further, similar to circuitregions 102/104 and 202/204 of semiconductor devices 100/200respectively, semiconductor device 300 includes circuit regions 302 and304. Because of the potential for circuit regions 302 and 304 varyingfrom device to device (as evidenced by comparing devices 100 and 200),these regions are omitted from selected eyepoint 310. Eyepoint 310includes bond pad group 306 (a column of bond pads including bond pads300 h, 300 i, 300 j, 300 k, 300 l, and 300 m) and bond pad group 308 (arow of bond pads including bond pads 300 a, 300 b, 300 c, 300 d, 300 e,300 f, 300 g). Certain features of eyepoint 310 (e.g., an outline shapeof each of the bond pads, the spacing of the bond pads with respect toone another, etc.) do not tend to vary from device to device, and assuch, a more robust teach process (and a more robust subsequent scan ofactual devices to be wirebonded) is provided.

It is noteworthy that while the eyepoint is referred to above aseyepoint 310 (which is the region within the dotted line in FIG. 3), itis understood that eyepoint 310 may only include certain shapes/featureswithin the region such as bond pad shapes and the respective locationsof certain bond pads within region 310. This is true for the variousexemplary embodiments of the present invention illustrated and describedherein.

Further, while exemplary eyepoint 310 includes the bond pad shapes ofthe bond pads in groups 306 and 308 (and excludes the shapes of circuitregions 302 and 304), an outline shape of one or both of circuit regions302 and 304 could be included in the eyepoint. In such an eyepoint, thepotential internal differences between the circuit regions that mayexist from device to device (e.g., the differences between circuitregion 102 in FIG. 1 as compared to circuit region 202 in FIG. 2) maynot affect the teaching process (and subsequent find process) becauseonly an outline shape of the circuit region is included in the eyepoint.

In some applications, semiconductor device bond pads may include “probemarks” that are visible to the vision system of a wire bonding machine.Such probe marks do not tend to be uniform. For example, because of themanner in which semiconductor wafers are typically tested, some of theprobe marks may extend in one direction (e.g., horizontal) while othersof the probe marks may extend in another direction (e.g., vertical).These variations of the probe marks on bond pads may also cause problemsin conventional eyepoint teaching systems (e.g., low find scoreproblems, MTBA problems, etc.).

According to certain exemplary embodiments of the present invention, aninterior region of the bond pads is ignored/excluded from the eyepointsuch that problems associated with certain variations (e.g., probemarks) is substantially limited. For example, such regions may be (1)scanned but not considered during the scoring process, (2) scanned butgiven relatively little weight during the scoring process, and/or (3)not scanned at all. Thus, it is clear that the terms “excluded”,“omitted”, “precluded”, and/or “masked” (or similar terms), whenreferring to certain areas of a device (e.g., shaded regions such as theinterior of bond pads or other shaded regions), does not necessarilymean that the areas are excluded from a scanning process (e.g., ascanning process during teaching, a scanning process during processingof an actual device to be wirebonded, etc.).

Thus, FIG. 4 illustrates semiconductor device 300 with certain selected(e.g., predetermined, dynamically determined in real-time, etc.) regionsomitted from eyepoint 310 a (in contrast to eyepoint 310 which hascertain differences from eyepoint 310 a, such as, eyepoint 310 does notomit the interior of the bond pads from the eyepoint). These selectedregions are shaded/hatched in FIG. 4 (i.e., the shaded regions may be“masked” from the eyepoint teach process, for example, where (1) analgorithm is configured to not scan these regions, and/or (2) thealgorithm is configured such that the presence of edges/features withinthe “masked” region does not contribute to the overall scorecalculation). As shown in FIG. 4, an interior of each of the bond padsis shaded such that the interior is excluded from the taught eyepoint.More specifically, interior 300 a 1 of bond pad 300 a is omitted fromeyepoint 310 a. The same is true for interior 300 b 1 of bond pad 300 b,interior 300 c 1 of bond pad 300 c, interior 300 d 1 of bond pad 300 d,interior 300 e 1 of bond pad 300 e, interior 300 f 1 of bond pad 300 f,interior 300 g 1 of bond pad 300 g, interior 300 h 1 of bond pad 300 h.Interior 300 l 1 of bond pad 300 i, interior 300 j 1 of bond pad 300 j,interior 300 k 1 of bond pad 300 k, interior 300 l 1 of bond pad 300 l,and interior 300 m 1 of bond pad 300 m.

In order to provide a small margin of error, and an area to locate theshapes, for (1) teaching the bond pads of eyepoint 310 a (e.g., theshapes and respective locations of the bond pads in eyepoint 310 a), and(2) later scanning of eyepoint 310 a, a region beyond the actual bondpads is also included in eyepoint 310 a. More specifically, a non-shadedregion 306 a is provided surrounding bond pad column 306, and anon-shaded region 308 a is provided surrounding bond pad row 308. Byproviding these surrounding regions, the likelihood of teaching theexact outline location of each of the bond pads (and their outlinelocation with respect to each other) in an eyepoint is increased.

FIG. 5 is a top view of a portion of semiconductor device 500 includingregion 510 selected to include an eyepoint in accordance with anexemplary embodiment of the present invention. Semiconductor device 500includes a number of bond pads. As illustrated in FIG. 5, a first groupof bond pads (including bond pads 500 a, 500 b, 500 c, 500 d, 500 e, 500f, 500 g, 500 h, 500 i, 500 j, 500 k, 500 l, 500 m, 500 n, 500 o, 500 p,500 q, 500 r, 500 s, 500 t, 500 u, and 500 v) are provided about aperiphery of semiconductor device 500, while a second group of bond pads(including bond pads 502 a, 502 b, 502 c, 502 d, 502 e, 502 f, 502 g,502 h, 502 i, 502 j, 502 k, 502 l, 502 m, 502 n, 502 o, 502 p, 502 q,502 r, 502 s, 502 t, 502 u, 502 v, 502 w, 502 x, 502 y, 502 z, and 502aa) are provided inside the first group. Semiconductor device 500 alsoincludes fiducial 504.

FIG. 6 is a detailed view of region 510 of semiconductor device 500selected to include an eyepoint of semiconductor device 500. Region 510includes bond pads 500 a, 500 b, 500 c, 500 d, 500 e, 500 f, 500 k, 500l, 500 m, 500 o, 502 g, 502 h, 502 i, 502 j, 502 k, 502 l, 502 m, 502 n,502 o, 502 p, 502 q and fiducial 504. Note that bond pads 502 n and 502o include some type of aberration that may be visible to a vision systemperforming a scan of the bond pad (e.g., a blemish, varyingreflectivity, a visible flaw, etc.). If semiconductor device 500(including the aberrations of bond pads 502 n and 502 o) is used as asample device to teach an eyepoint to a wire bonding machine, when it istime to process (e.g., wire bond) an actual semiconductor device usingthe eyepoint taught from semiconductor device 500, a number of potentialproblems may result (e.g., the score for semiconductor device to beprocessed being below a threshold value even though the device isacceptable for further processing, an undesirably low MTBA for devicessuch as semiconductor device 500, etc.).

According to certain exemplary embodiments of the present invention,known data about the semiconductor device (e.g., CAD data, a drawing, acomputer scan of a drawing, a priori data, etc.) may be used to assistin defining an eyepoint. For example, such data may be used to define aneyepoint that could otherwise include certain deficiencies of the samplesemiconductor device if the sample device was used to teach theeyepoint. More specifically, the known data (e.g., CAD data, a drawing,a computer scan of a drawing, a priori data, etc.) may be used to definethe eyepoint as shown in FIG. 7. Note that region 510 of semiconductordevice 500 as shown in FIG. 7 does not include the aberrations of bondpads 502 n and 502 o. By starting with the eyepoint including the shapesof region 510 illustrated in FIG. 7 (which is defined using the knowndata, and prior to the actual teaching of a sample device 500 on thewire bonding machine), the eyepoint 510 is initially defined withoutcertain deficiencies. Thereafter, when the defined eyepoint 510 isactually taught on the wire bonding machine (e.g., using sample device500 such as that shown in FIG. 6 with aberrations in pads 502 n and 502o), certain deficiencies may be omitted during the teaching processbecause only general information of the sample device (e.g., shape andrelative location of the bond pads and fiducial included in eyepoint510) is confirmed during the teaching on the wire bonding machine. Thus,an improved eyepoint is provided by utilizing (1) known data about thesemiconductor device in conjunction with (2) a sample device taught onthe wire bonding machine.

FIG. 8 is an illustration of a further improved eyepoint 510 a forsemiconductor device 500. More specifically, selected regions of theportion of semiconductor device 500 are omitted from eyepoint 510 a.These selected regions are shaded (i.e., the shaded regions may be“masked” from the eyepoint teach process) in FIG. 8. As shown in FIG. 8,an interior of each of the bond pads is shaded such that the interior isexcluded from the taught eyepoint. More specifically, interior 500 a 1of bond pad 500 a is omitted from eyepoint 510 a. The same is true forinterior 500 b 1 of bond pad 500 b, interior 500 c 1 of bond pad 500 c,as well as the interior of each of bond pads 500 d, 500 e, 500 f, 500 k,500 l, 500 m, 500 n, 500 o, 502 g, 502 h, 502 i, 502 j, 502 k, 502 l,502 m, 502 n, 502 o, 502 p, and 502 q. Likewise, interior 504 a 1 offiducial 504 is also omitted from eyepoint 510 a. Other shaded regionsrepresent, for example, regions that may have inconsistenttextures/reflectivities from device to device. As such, a score of adevice to be wirebonded may not be affected by such shaded areas.

Further, in order to provide a small margin of error, and an area tolocate the shapes, for (1) teaching the shapes/respective locations ofthe features of eyepoint 510 a (e.g., the shapes and respectivelocations of the bond pads and fiducial of eyepoint 510 a), and (2)later scanning of eyepoint 510 a, a region beyond the actual bond pads(and fiducial shape) is also included in eyepoint 510 a. Morespecifically, a non-shaded region 500 a 2 is provided surrounding bondpad 500 a, and a non-shaded region 500 b 2 is provided surrounding bondpad 500 b. Such a non-shaded region is provided (and illustrated in FIG.8) for each of bond pads 500 c, 500 d, 500 e, 500 f, 500 k, 5001, 500 m,500 n, 5000, 502 h, 502 i, 502 l, 502 k, 502 l, 502 m, 502 n, 5020, 502p, and 502 q. Likewise, a non-shaded region 504 a 2 is providedsurrounding fiducial 504. By providing these surrounding regions, thelikelihood of teaching the exact outline of each of the bond pads andthe fiducial (and their outline location with respect to each other) inan eyepoint is increased.

FIG. 9 is a top view of a portion of semiconductor device 600 includingregion 610 selected to include an eyepoint in accordance with anexemplary embodiment of the present invention. Semiconductor device 600includes a number of bond pads. As illustrated in FIG. 9, a first groupof bond pads (including bond pads 600 a, 600 b, 600 c, 600 d, 600 e, 600f, 600 g, 600 h, 600 i, 600 j, 600 k, 600 l, and 600 m) are provided ina first row on semiconductor device 600, while a second group of bondpads (including bond pads 602 a, 602 b, 602 c, 602 d, 602 e, 602 f, 602g, 602 h, 602 i, 602 j, 602 k, 602 l, 602 m, 602 n, 602 o, and 602 p)are provided in a second row.

FIG. 10 is a detailed view of region 610 of semiconductor device 600selected to include an eyepoint of semiconductor device 600. Region 610includes bond pads 600 a, 600 b, 600 c, 600 d, 600 e, 602 a, 602 b, 602c, 602 d, and 602 e. Note that bond pads 602 c and 602 d include sometype of aberration that may be visible to a vision system performing ascan of the bond pad (e.g., a blemish, varying reflectivity, a visibleflaw, etc.). If semiconductor device 600 (including the aberrations ofbond pads 602 c and 602 d) is used to teach an eyepoint to a wirebonding machine, when it is time to process (e.g., wire bond) an actualsemiconductor device using the eyepoint taught from semiconductor device600, a number of potential problems may result (e.g., the score forsemiconductor device to be processed being below a threshold value eventhough the device is acceptable for further processing, an undesirablylow MTBA for devices such as semiconductor device 600, etc.).

According to certain exemplary embodiments of the present invention,known data about the semiconductor device (e.g., CAD data, a drawing, acomputer scan of a drawing, a priori data, etc.) may be used to assistin defining an eyepoint. For example, such data may be used to correctan eyepoint that could include certain deficiencies of the samplesemiconductor device used to teach the eyepoint. More specifically, theknown data (e.g., CAD data, a drawing, a computer scan of a drawing, apriori data, etc.) may be used to define the eyepoint as shown in FIG.11. Note that region 610 of semiconductor device 600 as shown in FIG. 11does not include the aberrations of bond pads 602 c and 602 d. Bystarting with the eyepoint 610 illustrated in FIG. 11 (which is definedusing the known data, and prior to the actual teaching of a sampledevice 600 on the wire bonding machine), the eyepoint 610 is initiallydefined without certain deficiencies. Thereafter, when the definedeyepoint 610 is actually taught on the wire bonding machine (e.g., usingsample device 600 such as that shown in FIG. 10 with aberrations at bondpads 602 c and 602 d), certain deficiencies may be omitted during theteaching process because only general information of the sample device(e.g., shape and relative location of the bond pads included in eyepoint610) is confirmed during the teaching on the wire bonding machine. Thus,an improved eyepoint is provided by utilizing (1) known data about thesemiconductor device in conjunction with (2) a sample device taught onthe wire bonding machine.

FIG. 12 is an illustration of a further improved eyepoint 610 a forsemiconductor device 600. More specifically, selected regions of theportion of semiconductor device 600 are omitted from eyepoint 610 a.These selected regions are shaded (i.e., the shaded regions may be“masked” from the eyepoint teach process) in FIG. 12. As shown in FIG.12, an interior of each of the bond pads is shaded such that theinterior is excluded from the taught eyepoint. More specifically,interior 600 a 1 of bond pad 600 a is omitted from eyepoint 610 a. Thesame is true for interior 600 b 1 of bond pad 600 b, interior 600 c 1 ofbond pad 600 c, as well as the interior of each of bond pads 600 d, 600e, 602 a, 602 b, 602 c, 602 d, and 602 e.

Further, in order to provide a small margin of error, and an area tolocate the shapes, for (1) teaching the shapes/respective locations ofthe features of eyepoint 610 a (e.g., the shapes and respectivelocations of the bond pads eyepoint 610 a), and (2) later scanning ofeyepoint 610 a, a region beyond the actual bond pads is also includedeyepoint 610 a. More specifically, a non-shaded region 600 a 2 isprovided surrounding bond pad 600 a, and a non-shaded region 600 b 2 isprovided surrounding bond pad 600 b. Such a non-shaded region isprovided (and illustrated in FIG. 12) for each of bond pads 600 c, 600d, 600 e, 602 a, 602 b, 602 c, 602 d, and 602 e. By providing thesesurrounding regions, the likelihood of teaching the exact outline ofeach of the bond pads in an eyepoint (and their outline location withrespect to each other) is increased.

FIG. 13 is a top view of a portion of semiconductor device 700 includingregion 710 selected to include an eyepoint in accordance with anexemplary embodiment of the present invention. Semiconductor device 700includes a number of bond pads. As illustrated in FIG. 13, a first groupof bond pads (including bond pads 700 a, 700 b, 700 c, 700 d, 700 e, 700f, 700 g, 700 h, 700 i, 700 j, 700 k, 700 l, 700 m, 700 n, 700 o, 700 p,700 q, 700 r, 700 s, 700 t, 700 u, and 700 v) are provided about aperiphery of semiconductor device 700, while a second group of bond pads(including bond pads 702 a, 702 b, 702 c, 702 d, 702 e, 702 f, 702 g,702 h, 702 i, 702 j, 702 k, 702 l, 702 m, 702 n, 702 o, 702 p, 702 q,702 r, 702 s, 702 t, 702 u, 702 v, 702 w, 702 x, 702 y, 702 z, and 702aa) are provided inside the first group.

FIG. 14 is a detailed view of region 710 of semiconductor device 700selected to include an eyepoint of semiconductor device 700. Region 710includes bond pads 700 a, 700 b, 700 c, 700 d, 7001, 700 m, 700 n, 700o, 702 a, 702 b, 702 c, 702 m, 702 n, and 702 o. Note that bond pads 702n and 702 o include some type of aberration that may be visible to avision system performing a scan of the bond pad (e.g., a blemish,varying reflectivity, a visible flaw, etc.). If semiconductor device 700(including the aberrations of bond pads 702 n and 702 o) is used toteach an eyepoint to a wire bonding machine, when it is time to process(e.g., wire bond) an actual semiconductor device using the eyepointtaught from semiconductor device 700, a number of potential problems mayresult (e.g., the score for semiconductor device to be processed beingbelow a threshold value even though the device is acceptable for furtherprocessing, an undesirably low MTBA for devices such as semiconductordevice 700, etc.).

According to certain exemplary embodiments of the present invention,known data about the semiconductor device (e.g., CAD data, a drawing, acomputer scan of a drawing, a priori data, etc.) may be used to assistin defining an eyepoint. For example, such data may be used to correctan eyepoint that could include certain deficiencies of the samplesemiconductor device used to teach the eyepoint. More specifically, theknown data (e.g., CAD data, a drawing, a computer scan of a drawing, apriori data, etc.) may be used to define the eyepoint as shown in FIG.15. Note that region 710 of semiconductor device 700 as shown in FIG. 15does not include does not include the aberrations of bond pads 702 n and702 o. By starting with the eyepoint 710 illustrated in FIG. 15 (whichis defined using the known data, and prior to the actual teaching of asample device 700 on the wire bonding machine), the eyepoint 710 isinitially defined without certain deficiencies. Thereafter, when thedefined eyepoint 710 is actually taught on the wire bonding machine(e.g., using sample device 700 such as that shown in FIG. 13 withaberrations at bond pads 702 n and 702 o), certain deficiencies may beomitted during the teaching process because only general information ofthe sample device (e.g., shape and relative location of the bond padsincluded in eyepoint 710) is confirmed during the teaching on the wirebonding machine. Thus, an improved eyepoint is provided by utilizing (1)known data about the semiconductor device in conjunction with (2) asample device taught on the wire bonding machine.

FIG. 16 is an illustration of a further improved eyepoint 710 a forsemiconductor device 700. More specifically, selected regions of theportion of semiconductor device 700 are omitted from eyepoint 710 a.These selected regions are shaded (i.e., the shaded regions may be“masked” from the eyepoint teach process) in FIG. 16. As shown in FIG.16, an interior of each of the bond pads is shaded such that theinterior is excluded from the taught eyepoint. More specifically,interior 700 a 1 of bond pad 700 a is omitted from eyepoint 710 a. Thesame is true for interior 700 b 1 of bond pad 700 b, interior 700 c 1 ofbond pad 700 c, as well as the interior of each of bond pads 700 d, 700l, 700 m, 700 n, 700 o, 702 a, 702 b, 702 c, 702 m, 702 n, and 702 o.

Further, in order to provide a small margin of error, and an area tolocate the shapes, for (1) teaching the shapes/respective locations ofthe features of eyepoint 710 a (e.g., the shapes and respectivelocations of the bond pads eyepoint 710 a), and (2) later scanning ofeyepoint 710 a, a region beyond the actual bond pads is also included ineyepoint 710 a. More specifically, a non-shaded region 700 a 2 isprovided surrounding bond pad 700 a, and a non-shaded region 700 b 2 isprovided surrounding bond pad 700 b. Such a non-shaded region isprovided (and illustrated in FIG. 16) for each of bond pads 700 c, 700d, 700 l, 700 m, 700 n, 700 o, 702 a, 702 b, 702 c, 702 m, 702 n, and702 o. By providing these surrounding regions, the likelihood ofteaching the exact outline of each of the bond pads in an eyepoint (andtheir outline location with respect to each other) is increased.

FIG. 17 is a top view of a portion of semiconductor device 800 includingregion 810 selected to include, an eyepoint in accordance with anexemplary embodiment of the present invention. Semiconductor device 800includes a number of bond pads. As illustrated in FIG. 17, semiconductordevice includes bond pads 800 a, 800 b, 800 c, 800 d, 800 e, 800 f, 800g, 800 h, 800 i, 800 j, and 800 k. Semiconductor device 800 alsoincludes circuit element 804.

As outlined in FIG. 17, region 810 of semiconductor device 800 includesbond pads 800 a, 800 b, 800 c, 800 d, 800 h, 800 i, and 800 j, as wellas circuit element 804. Thus, it is clear that shapes (and respectivelocations) of portions of semiconductor devices other than bond pads andfiducials (such as circuit element 804 which may be a wiring pattern, aconductive trace pattern, and/or the like) are also contemplated for useas part of an eyepoint.

FIG. 18 is an illustration of a further improved eyepoint 810 a forsemiconductor device 800. More specifically, selected regions of theportion of semiconductor device 800 are omitted from eyepoint 810 a.These selected regions are shaded (i.e., the shaded regions may be“masked” from the eyepoint teach process) in FIG. 18. As shown in FIG.18, an interior of each of the bond pads is shaded such that theinterior is excluded from the taught eyepoint. More specifically,interior 800 a 1 of bond pad 800 a is omitted from eyepoint 810 a. Thesame is true for interior 800 b 1 of bond pad 800 b, interior 800 c 1 ofbond pad 800 c, as well as the interior of each of bond pads 800 d, 800h, 800 i, and 800 j, as well as interior portion 804 a 1 of circuitelement 804 a.

Further, in order to provide a small margin of error, and an area tolocate the shapes, for (1) teaching the shapes/respective locations ofthe features of eyepoint 810 a (e.g., the shapes and respectivelocations of the bond pads, as well as circuit element 804, of eyepoint810 a), and (2) later scanning of eyepoint 810 a, a region beyond theactual bond pads, as well as beyond circuit element 804, is alsoincluded in eyepoint 810 a. More specifically, a non-shaded region 800 a2 is provided surrounding bond pad 800 a, and a non-shaded region 800 b2 is provided surrounding bond pad 800 b. Such a non-shaded region isalso provided (and illustrated in FIG. 18) for each of bond pads 800 c,800 d, 800 h, 800 i, and 800 j, as well as for circuit element 804. Byproviding these surrounding regions, the likelihood of teaching theexact outline of each of the bond pads (and an outline of circuitelement 804) in an eyepoint (and their outline location with respect toeach other) is increased.

FIG. 19 is a top view of semiconductor device 900. As shown in FIG. 19,two distinct eyepoints (i.e., eyepoint 910 a and eyepoint 910 b) havebeen defined. Thus, it is clear that the teachings of the presentinvention disclosed herein, through its various exemplary embodiments,are applicable to wire bonding operations utilizing multiple eyepoints.

While various of the figures provided herein illustrate a semiconductordie alone, it is understood that during processing steps such as wirebonding, the semiconductor die has typically been bonded (e.g.,die-bonded using an adhesive or the like) to a support structure such asa leadframe or a substrate. FIG. 20 is a top view of a portion ofsemiconductor device 1000 (e.g., a semiconductor die 1000) bonded toleadframe 1050.

Semiconductor device 1000 includes bond pads 1000 a, 1000 b, 1000 c,1000 d, 1000 e, 1000 f, 1000 g, 1000 h, 1000 i, 1000 j, and 1000 k.Eyepoint 1010 is selected to include bond pads 1000 a, 1000 b, 1000 c,1000 d, 1000 h, 1000 i, and 1000 j. Leadframe 1050 includes a pluralityof “leads” including leads 1050 a, 1050 b, 1050 c, 1050 d, and 1050 e.During processing of semiconductor devices (e.g., wire bonding) itsometimes happens that a device that has already been wire bonded is puton the wire bonding machine. For example, this may be an error.Alternatively, it may be that a portion of the device has been wirebonded, but that another portion of the device still needs to bewirebonded. It is very desirable to know if a device on a wire bondingmachine has been wire bonded or not. For example, if this is not known,a device that has already been wire bonded may be subjected to furtherunintended wire bonding in which case the device may be destroyed orotherwise rendered worthless.

According to an exemplary embodiment of the present invention, a methodof determining if a device has been wire bonded is provided. As shown inFIG. 20 a number of wire loops 1002 a, 1002 b, 1002 c, 1002 h, and 1002i are illustrated. More specifically, wire loop 1002 a (including ballbond 1002 a 1 bonded to bond pad 1000 a) provides electricalinterconnection between bond pad 1000 a and lead 1050 a; wire loop 1002b (including ball bond 1002 b 1 bonded to bond pad 1000 b) provideselectrical interconnection between bond pad 1000 b and lead 1050 b; wireloop 1002 c (including ball bond 1002 c 1 bonded to bond pad 1000 c)provides electrical interconnection between bond pad 1000 c and lead1050 c; wire loop 1002 h (including ball bond 1002 h 1 bonded to bondpad 1000 h) provides electrical interconnection between bond pad 1000 hand lead 1050 d; and wire loop 1002 i (including ball bond 1002 i 1bonded to bond pad 1000 i) provides electrical interconnection betweenbond pad 1000 i and lead 1050 e. Using a pattern recognition methodand/or system such as those described above with respect to teachingshapes and relative locations of shapes (e.g., bond pad shapes andrelative locations of bond pad shapes), a shape of a portion of a wireloop may be recognized. More specifically, an algorithm may beconfigured to search the bond pads of a semiconductor die to determineif a wire has been bonded thereto. In the example illustrated in FIG.20, the algorithm may be configured to search for the shape of a ballbond (e.g., a circle, an ellipse, etc.) on a bond pad to see if a wirehas been bonded thereto.

Further features of this aspect of the present invention may also beprovided. For example, the eyepoint (e.g., eyepoint 1010 illustrated inFIG. 20) may be selected to include the bond pads that will be wirebonded first during the wire bonding process. With respect to FIG. 20,bond pad 1000 a may be the first bond pad to be wirebonded. Thus,eyepoint 1010 is selected to include this bond pad. As such, during theprocess of using pattern recognition to see if a wire has been bonded toa bond pad (e.g., by looking for a shape of a ball bond on the bondpad), the likelihood of seeing a bonded wire (e.g., wire loop 1002 a) isgreater because the selected eyepoint includes the first pad that wouldhave been wire bonded.

Further, a method of determining if a wire has been bonded to a pad ofthe semiconductor device may be integrated into a process of teaching aneyepoint. For example, in a first step a teaching process for teachingan eyepoint according to the present invention may be carried out. In asecond step, a distinct teaching process for teaching a second eyepoint(the eyepoint for checking for bonded wires) may be taught.Subsequently, when a device to be wirebonded is on the machine,confirmation of the position and/or alignment of the device could bedone using the first taught eyepoint. Then, once the position and/oralignment of the device has been confirmed, a second scan may becompleted to see if there were any bonded wires. In such an embodiment,the first eyepoint may have the interior of the bond pads masked (as inFIGS. 4, 8, 12, 16, and 18) while the second eyepoint does not have theinterior of the bond pads masked (such that the interior of the bondpads may be scanned for ball bond shapes).

In another alternative embodiment, a single eyepoint may be taught, anda single scan of an actual device to be wirebonded may be completed. Insuch an embodiment, at least a portion of interiors of the bond pads inthe eyepoint may not be masked such that the interior of the bond padsmay be scanned for ball bond shapes.

While the methods of determining if bond pads have been wirebonded havebeen described (and illustrated in the example of FIG. 20) in connectionwith wire loops (i.e., wire loops extending between a bond pad and alead of a leadframe), it is understood that the wire bonds being checkedmay have varying forms such as conductive bumps (e.g., stud bumps or thelike).

FIGS. 21-22 are flow diagrams in accordance with certain exemplaryembodiments of the present invention. As is understood by those skilledin the art, certain steps included in the flow diagrams may be omitted;certain additional steps may be added; and the order of the steps may bealtered from the order illustrated.

More specifically, FIG. 21 is a flow diagram illustrating a method ofteaching an eyepoint for a wire bonding operation in accordance with anexemplary embodiment of the present invention. At step 2100, a group ofshapes is selected from a region of a semiconductor device for use as aneyepoint. For example, the group of shapes may include bond pad shapes,fiducial shapes, circuitry shapes, amongst others. At step 2102, theeyepoint is taught to a wire bonding machine using at least one of (a) asample semiconductor device or (b) predetermined data related to thesemiconductor device. This teaching step includes defining locations ofeach of the shapes with respect to one another. Such locations may bedefined to include an area surrounding each of the group of shapes. Theeyepoint may be defined to include the group of shapes while maskingpredetermined areas of the region (i.e., step 2104) such that thepredetermined areas are precluded from the eyepoint. For example, suchmasking may include using an algorithm to preclude the location of thepredetermined areas of the region from the eyepoint. Such masking mayinclude masking at least one of (1) interior portions of selected bondpads, and (2) portions of the region between bond pads. At optional step2106, a second eyepoint is taught to the wire bonding machine. Thesecond eyepoint corresponds to a shape of a portion of a wire loop on abond pad of the semiconductor device. For example, the shape of theportion of the wire loop may correspond to the shape of a ball bond ofthe wire loop.

FIG. 22 is a flow diagram illustrating a method of operating a wirebonding machine. Steps 2200, 2202, 2204, and 2206 of the illustratedmethod correspond to steps 2100, 2102, 2104, and 2106 of the flowdiagram illustrated at FIG. 21. At step 2208, a first semiconductordevice configured to be wire bonded is indexed into a predeterminedposition (e.g., the bond site) of the wire bonding machine. At step2210, selected portions of the first semiconductor device are scannedusing a vision system of the wire bonding machine, where the selectedportions correspond to the taught eyepoint (e.g., the eyepoint taight atstep 2202). At step 2212, a percentage score is assigned to the firstsemiconductor device by comparing the taught eyepoint to the selectedportions of the first semiconductor device. Following step 2212, it maybe determined that the position of the first semiconductor device shouldbe adjusted prior to the wire bonding operation. At step 2214, aposition of the first semiconductor device is adjusted at leastpartially based on a result of comparing the taught eyepoint to theselected portions of the first semiconductor device. At step 2216, wireloops are created (e.g., wire bonded) between bond pads of the firstsemiconductor and another bonding location. Thus, an improved operationof a wire bonding machine is provided.

As is understood by those skilled in the art, the first semiconductordevice described above (e.g., described with respect to steps 2208,2210, etc.) is not necessarily the first device indexed after the teachprocess. The term “first” is used simply to differentiate the devicefrom the sample device described, for example, at step 2102. It isunderstood that a plurality of devices may be indexed, scanned, etc. inorder to determine what an acceptable score is, and what is not anacceptable score.

Although the present invention has been described primarily with respectto (1) defining/teaching an eyepoint in a location of a sample device,and then (2) scanning the corresponding location of a device to be wirebonded to confirm that the device to be wire bonded is acceptable, it isnot limited thereto. In certain applications, it may occur that thedevice (e.g., at the bond site) has moved, or that the orientation ofthe device at the bond site is not known. In such a situation, aneyepoint (i.e., that is defined/taught according to any exemplaryembodiment of the present invention) may be found by scanning the deviceto be wirebonded. For example, if an eyepoint includes five (5) bondpads having predetermined shapes/sizes and predetermined locations withrespect to one another (e.g., predetermined being through the teachprocess), the position of a semiconductor device to be wire bonded maybe determined by scanning the device and locating a featurecorresponding to the taught eyepoint. Of course, the teaching of such aneyeppoint may be accomplished through any of the exemplary methodsdescribed herein such as: (1) automatically generating the eyepoint(e.g., generated using a prior data), (2) generating the eyepoint usingoperator intervention, and/or (3) scanning a region of the deviceincluding the eyepoint (e.g., using a single field of view, usingmultiple fields of view aggregated, etc.).

Although the present invention has been described primarily with respectto eyepoints utilized to properly position and/or align a semiconductordevice (e.g., a semiconductor die) prior to wire bonding (or otherprocessing such as stud bumping, device inspection, etc) of the device,it is not limited thereto. The teachings provided herein are alsoapplicable to teaching eyepoints for a variety of other applications.For example, it is typical to teach a leadframe or other substrate priorto wire bonding a semiconductor die thereto. Further, in someapplications, a semiconductor die or leadframe may be taught prior tothe semiconductor die being die-bonded to the leadframe. Thus, themethods described herein (e.g., portions of the methods illustrated inFIGS. 21-22) may also be applied to alignment done in connection with adie bonding operation. As such, the various exemplary embodiments of thepresent invention may also be applied to eyepoint recognition withrespect to these and other applications.

Although the invention is illustrated and described herein withreference to specific embodiments, the invention is not intended to belimited to the details shown. Rather, various modifications may be madein the details within the scope and range of equivalents of the claimsand without departing from the invention.

1. A method of teaching an eyepoint for a wire bonding operation, themethod comprising the steps of: (1) selecting a group of shapes from aregion of a semiconductor device for use as an eyepoint, the group ofshapes including at least one of (a) bond pad shapes, (b) fiducialshapes, and (c) circuitry shapes; (2) teaching the eyepoint to a wirebonding machine using at least one of (a) a sample semiconductor device,or (b) predetermined data related to the semiconductor device, theteaching step including defining locations of each of the shapes withrespect to one another to bind the selected shapes together as theeyepoint; (3) scanning a region of another semiconductor device using avision system of a wire bonding machine to locate a feature of theanother semiconductor device corresponding to the taught eyepoint; and(4) assigning a score to the another semiconductor device by comparingthe taught eyepoint to the feature located at the scanned region.
 2. Themethod of claim 1 wherein step (1) includes selecting the group ofshapes to include a plurality of bond pad shapes.
 3. The method of claim1 wherein step (1) includes selecting the group of shapes to include aplurality of bond pad shapes and at least one fiducial shape.
 4. Themethod of claim 1 further comprising the step of (3) defining theeyepoint to include the group of shapes while masking predeterminedareas of the region such that the predetermined areas are precluded fromthe eyepoint.
 5. The method of claim 4 wherein the step of maskingincludes masking at least one of (1) interior portions of selected bondpads, and (2) portions of the region between bond pads.
 6. The method ofclaim 1 wherein step (2) includes defining the locations to include anarea surrounding each of the group of shapes.
 7. The method of claim 1further comprising the step of (3) teaching a second eyepoint to thewire bonding machine, the second eyepoint corresponding to a shape of aportion of a wire loop on a bond pad of the semiconductor device.
 8. Themethod of claim 7 wherein the shape corresponds to the shape of a ballbond of the wire loop.
 9. The method of claim 1 wherein the eyepointtaught by the method is configured to be a back-up eyepoint of the wirebonding operation.
 10. A method of operating a wire bonding machine, themethod comprising the steps of: (1) selecting a group of shapes from aregion of a semiconductor device for use as an eyepoint, the group ofshapes including at least one of (a) bond pad shapes, (b) fiducialshapes, and (c) circuitry shapes; (2) teaching the eyepoint to the wirebonding machine using at least one of (a) a sample semiconductor device,or (b) predetermined data related to the semiconductor device, theteaching step including defining locations of each of the shapes withrespect to one another to bind the selected shapes together as theevepoint; (3) indexing another semiconductor device configured to bewire bonded into a predetermined position of the wire bonding machine;(4) scanning selected portions of the first another semiconductor deviceusing a vision system of the wire bonding machine to locate a feature ofthe another semiconductor device corresponding to the taught eyepoint;and (5) assigning a score to the another semiconductor device bycomparing the taught evepoint to the scanned feature.
 11. The method ofclaim 10 wherein step (1) includes selecting the group of shapes toinclude a plurality of bond pad shapes.
 12. The method of claim 10wherein step (1) includes selecting the group of shapes to include aplurality of bond pad shapes and at least one fiducial shape.
 13. Themethod of claim 10 further comprising the step of (3) defining theeyepoint to include the group of shapes while masking predeterminedareas of the region such that the predetermined areas are precluded fromthe eyepoint.
 14. The method of claim 13 wherein the step of maskingincludes masking at least one of (1) interior portions of selected bondpads, and (2) portions of the region between bond pads.
 15. The methodof claim 10 wherein step (2) includes defining the locations to includean area surrounding each of the group of shapes.
 16. The method of claim10 further comprising the step of (5) teaching a second eyepoint to thewire bonding machine, the second eyepoint corresponding to a shape of aportion of a wire loop on a bond pad of the semiconductor device. 17.The method of claim 16 wherein the shape corresponds to the shape of aball bond of the wire loop.
 18. The method of claim 10 wherein theeyepoint taught at step (2) is configured to be a back-up eyepoint ofthe wire bonding operation.
 19. The method of claim 10 furthercomprising the step of adjusting a position of the another semiconductordevice at least partially based on a result of comparing the taughteyepoint to the scanned feature.
 20. The method of claim 10 furthercomprising the step of creating wire loops between bond pads of theanother semiconductor and another bonding location.